


Siren

by darnedchild



Category: Sherlock (TV)
Genre: F/M, Halloween at 221B - A Sherlolly Celebration, Mer!Molly, TAB era, human/mermaid relations of a physical nature, i warned for violence because there is a small amount of gore, monster!lock
Language: English
Status: In-Progress
Published: 2020-10-31
Updated: 2020-10-31
Packaged: 2021-03-09 02:01:33
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 1,759
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27306703
Author URL: https://archiveofourown.org/users/darnedchild/pseuds/darnedchild
Summary: Woman or sea creature - did it really matter?  Molly was as mysterious and beautiful as she was vicious; her very existence a scientific improbability.  From the moment he saw her, his fate was set, Sherlock would never let a mystery remain unsolved.
Relationships: Sherlock Holmes & John Watson, Sherlock Holmes/Molly Hooper
Comments: 6
Kudos: 32
Collections: 2020 Halloween at 221B - A Sherlolly Celebration





	Siren

**Author's Note:**

  * For [sunken_standard](https://archiveofourown.org/users/sunken_standard/gifts).



> If the first scene of this fic looks a bit familiar, it’s because I also posted it as part of my Universally Monstrous series. Those fics are all one shots on the shorter side, and this thing… this thing sort of ballooned on me.
> 
> At one point I posted that I was trying to come up with a plot that didn’t sound like a ripoff of “The Shape of Water” for the Creature from the Black Lagoon fic, but then @sunken-standard left me a comment that has stuck with me ever since – “If it ain’t broke don’t fix it, though. Let Molly bang the fishman.”
> 
> Then I remembered a made-for-cable-tv movie from 2001 called “She Creature”. When you mix that, “The Shape of Water”, and some Molly and Sherlock …
> 
> This fic is dedicated to you, @sunken-standard. 
> 
> Does it count as bestiality if someone is a gillman/sea creature? I don’t want to google that so let’s just pretend it doesn’t.

**Siren**

_The Molly Malone – Docked at the Port of Tilbury – 1895_

The stink of rotting fish and something worse tainted the air, assaulting Sherlock’s sensitive sense of smell. He briefly considered pulling out his handkerchief to cover his nose; but decided it wouldn’t do to risk offending the local fishermen.

At least until he had gotten what he’d come for.

His carriage came to a bumpy stop. Even as he exited, his driver was questioning the closest dock worker for the location of the _Molly Malone_. 

She was a small vessel in comparison to many of her counterparts moored nearby. Built to transport cargo rather than passengers. Older but well kept, indicating the Skipper cared for his ship and crew. Not the kind of ship a common conman would helm.

Interesting. 

Still, he knew better than most that appearances could be deceiving. 

The Skipper was waiting to welcome him aboard.

_A charlatan eager to show off his wares to an unsuspecting rube?_

Sherlock followed the Skipper down into the hold. In the middle of the otherwise empty space was a large tank full of murky water. The other man slowed as he approached the tank, stopping well away from the glass enclosure.

There was something roughly the size and shape of a human curled upon itself in a back corner of the tank, although the dim light of the lanterns and the filthy water made it difficult to discern much more.

“There she is.”

The “creature” in the tank stirred at the sound of the Skipper’s voice. What he first assumed to be arms wrapped around its body began to unfurl with slow, deliberate movements; revealing what could only be described as the forked tail fins of some kind of a marine animal. 

The rest of its body came into view. The torso was bare of clothing and clearly feminine in nature. If he were another man, Sherlock might turn his gaze away in an effort to protect her modesty. Instead, he watched intently as she planted her hands against the floor of the tank and propelled herself across the too-small enclosure to the pane of glass closest to him. 

In contrast to the human appearance of her upper body, her scaled lower half was long enough to coil upon itself and terminated in the forked tail fins he’d glimpsed earlier. 

Her hair was long; black or brown, it was difficult to tell as it drifted in the gentle ebb of the water. Now that she was near, he could see that her facial features were soft. Watson might call them elfin in one of his fanciful stories.

He stepped closer. Out of the corner of his eye, he saw the Skipper tense; but the other man remained silent.

Sherlock tilted his head as he continued to catalogue the creature’s appearance.

There were multiple odd folds of skin along the sides of her neck that seemed to subtly flutter in time with the rise and fall of her chest.

 _Gills?_ his mind supplied, even though he knew the concept was ludicrous at best.

He realized she had also tilted her head to the side, as if to mimic him. As a matter of fact, she appeared to be studying him just as intently as he had her. Her brown eyes were bright and intelligent, even through the dull veil of filthy water. She held his gaze for an uncomfortably long moment, before her lips titled upward in a hint of a smile.

“What do you think?” the Skipper asked, pride heavy in his voice.

“I think I’m looking at a fake, albeit a well-constructed one.” The Skipper huffed, but Sherlock ignored him. Surely the woman in the tank would need to surface soon, or risk betraying the presence of a breathing apparatus of some sort. His mind raced to calculate how long the average human female could survive without air before losing consciousness.

“She’s as real as you or I.”

Sherlock scoffed, “Impossible.” Yet, even as he spoke, he began to feel an uncharacteristic shadow of doubt.

She pressed her hand against the glass. He found himself taking another step closer to the tank with his hand upraised to return the gesture before he caught himself.

Her hand was small.

 _“Delicate,”_ Watson’s unwelcome voice intruded upon his thoughts.

But her fingers were tipped in the nails of a predator; short but deadly, as if designed by nature itself to pierce and rend.

His doubts continued to grow. There was no possible way that the woman before him was anything more than an elaborate prank. Was there?

 _“Impossible or merely improbable?”_ Mycroft asked, as if leading him toward a deduction like a dog on a leash.

“What do you call her?” Sherlock continued to keep his attention on the tank as he spoke to the Skipper.

“We named her Molly.”

“In honour of the ship and her crew, I presume?”

“Aye. It seemed fitting at the time.”

Sherlock noted the past tense. “But not now?” 

He briefly glanced at the Skipper. The other man looked uneasy, but he kept his mouth shut.

Molly’s earlier smile hardened and grew smug, as if she held some piece of knowledge that Sherlock was not privy to. Whatever it was, he wanted it.

Clearly, whether she was human or some fabled creature from the watery depths, Molly could understand what they were saying. 

“How long have you had her?”

“A few days,” the Skipper was quick to answer.

Too quick.

Sherlock turned to stare the man down.

“A week.”

Sherlock arched his brow.

“A month.”

That seemed plausible. Sherlock was content to let the matter drop for the moment. Especially with something far more important to unearth. “What happened to convince you to surrender her?”

The Skipper flexed his hand at his side, curling the fingers into a fist. “What do you mean?

“Come, come, man. Surely you realized that putting the creature on display would be far more profitable than selling her to the British government.” Sherlock’s eyes narrowed as he considered the evidence before him. “The crudely constructed barricade across the top of the tank, with no means to remove the bars should she needs to be released. An unplanned addition constructed in haste.”

He turned to face the Skipper fully. “You’ve kept a cautious distance… No, not cautious. Fearful. You’re scared of her.”

The Skipper blanched and Sherlock knew he was correct.

“I ask again, what happened?”

“There was an accident. She grew listless after a few days. Stayed at the bottom of the tank. Refused the fish we’d been giving her. I started to worry. The whole crew did. Like you said, she was worth far more to us alive than dead.” The Skipper closed his eyes for a moment and took a deep breath, as if steeling himself for what he was going to say next. 

“Nelson thought she might be temped by something fresher, on account of her being used to catching live fish and whatnot for her supper. The next time we brought up a net, he set a few aside in a bucket and brought them to her.” The other man refused to look at the creature. “He said he climbed a stack of crates and leaned over the side to offer the fish, and that’s all he remembers until we found him over there.” He jerked his head toward an area to the side of the tank. 

“He was screamin’ and bleedin’, soaking wet, clutching his hand to his chest like a wee babe. He must have lost his balance. Cut himself on the glass or a jagged bit of metal trying to catch himself when he fell in and severed two of his fingers.” He finally met Sherlock’s eyes, and the detective knew that the Skipper didn’t actually believe a word he’d just said. “We… never found them.”

Sherlock looked at the creature and noticed that the upward tilt of her thin lips had parted in a large, predatory grin to reveal a mouthful of dangerously sharp teeth. There was no doubt in his mind as to where Nelson’s missing digits had gone. “I’ve seen enough.”

“Aye. And your verdict? Will you take her?”

“That’s not my decision to make. Someone will be in contact with you soon enough, regardless.”

The Skipper looked as if he were about to argue, but a quelling look from Sherlock had him biting his tongue. “Best let you be on your way, then.”

They’d barely made it two steps toward the door of the hold when a sweet trill filled the room. Sherlock turned to find that Molly had wrapped her hands around the bars at the top of the tank and pulled herself up until her face was just above the waterline. She opened her mouth and the sound issued forth once more, rising and falling like a melody. Her song called to him, and he found himself swaying on his feet.

“That will be enough of that,” the Skipper snarled. 

Molly slowly lowered herself and returned to the far corner to curl up once more. She kept her eyes trained on him the entire time.

_The Diogenes Club - 1895_

The Diogenes club was as silent as a tomb. Sherlock ignored the club members he passed on the way to Mycroft’s usual room.

His brother was settled into his favourite chair, wide and substantial to support his expansive girth. He was surrounded by an array of dishes, sweet and savoury alike. The petite four in his hand was nearly invisible in the grasp of his massive fingers. He popped it into his mouth with obvious enjoyment before he nodded to acknowledge Sherlock.

Sherlock rolled his eyes in return and began to pace the room, already bored with their usual song and dance.

“Brother dear, you come bearing news, I trust?”

“I’ve seen her,” he confirmed.

Mycroft raised a brow. “Her?”

Sherlock mentally berated himself for his slip of the tongue. “ _It_ appears to be female.”

Even though Mycroft refrained from commenting any further, Sherlock knew he’d filed the moment away to review later. “And? Is it genuine?”

“Genuine enough to warrant further study.”

“Excellent.” Mycroft celebrated with another petite four. “I’ll arrange to have it acquired immediately.”

Sherlock continued to pace in front of the room’s large fireplace.

“Is there more, brother?”

Until Mycroft asked, Sherlock hadn’t been able to identify what, exactly, had made him so restless. Suddenly he knew. “What are you planning to do with—it?”

“Study it.” Mycroft smirked. “Just as you suggested.”


End file.
